1. Field of the Invention
This invention relates to the field of apparatus for providing a gas such as oxygen to the breathing passages of a user.
2. Background Art
Certain diseases or injuries may cause a patient to require prolonged administration of oxygen or other gases. For example, someone afflicted with lung emphezema or a bedridden patient in a hospital, nursing home, etc., may require the administration of oxygen or some other gas to maintain the patient's breathing or for some other therapeutic purpose.
One method of administering therapeutic oxygen to a patient is the use of a nasal cannula. In a nasal cannula, there is provided some means to direct a stream of gas (e.g. oxygen) into the nares of the patient requiring gas. The nares is a cavity formed in the inner nasal passage of a patient. Typically, nasal cannulae employ a pair of tubes or nozzles that project into the nares and are in turn connected to a gas supply which continuously provides the desired gas to the patient's nasal passages.
Generally, nasal cannulea have been placed on the patient so as to be positioned between the patient's upper lip and nostrils. The cannula is held in place by means of a strap extending around the patient's head. The strap may be comprised of the oxygen supply line itself or a separate means such as for example elastic. One such cannula is illustrated in U.S. Pat. No. 3,513,844.
Another method of maintaining the position of the nasal cannula is shown in U.S. Pat. No. 4,278,082. In this method, the oxygen supply lines are looped behind a patient's ears and joined beneath the patient's chin where a cinching means is used to tighten the supply lines, producing tension and securing the cannula in place.
Regardless of the method of attachment, cannula which are positioned in such a manner invariably lead to irritation, potential infection and/or ulceration of the patient's tissue. There is also a great deal of discomfort and inconvenience, particularly in talking or eating, when the device is rigidly held in place. If there is no give to the positioning straps, head movement, eating and talking will result in an increase or decrease in tension, resulting in increased irritation or improper positioning of the cannula. Further, the bulk of prior art nasal cannulae tend to be heavy, conspicuous and uncomfortable.
In order to minimize the irritant effect on the skin between the nostrils and upper lip of a patient, the prior art has attempted to hold the cannula in place by means of a pressure fit within the nasal passages of the nose itself. One such method is illustrated in Swedish Pat. No. 174,607. However, such an approach results in traumatization of the sensitive tissues in the nasal passages and in addition, the tips utilized to provide such a fit also often result in occlusion of the nasal passages during exhaling and inhaling.
Therefore, it is an object of the present invention to provide a nasal cannula in which no head straps are required to maintain the cannula in position.
It is another object of the present invention to provide a nasal cannula having less bulk resting on the patient's face than prior art nasal cannulae.
It is yet another object of the present invention to provide a nasal cannula which will also maintain proper alignment and fit.
It is still another object of the present invention to provide a nasal cannula which does not create pressure trauma or irritation of the patient's face or nasal passages.
It is yet still another object of the present invention to provide a nasal cannula which provides greater comfort to the patient while still insuring consistent delivery of gas to the patient.